Yeah, I forgot about about PS3, it would allow MVSC2 plus some other good fighters, and you can use a Cthulhu PC/PS3 (which I have myself, and can recommend), which doesn't recquire soldering.
Or you can do the Multi Console Cthulhu (PS3/PS2/PC/Dreamcast through a PS2 to Dreamcast adapter, which I used aslo). Multi console is a little more complicated if you want to do something with quick connect rj-45 plugs for various system controls through one stick.
If this is your first time ever I suggest just buying the Multi Cthulhu and wiring it up for just PC/PS3 and you can always worry about the extra consoles later.
A quick rundown of wiring up controls:
each button and direction on a stick is connected to a microswitch. The miscroswitch has 3 prongs. One is GND/COMMON and one is for Normally Open (NO) and the last is for Normally Closed (NC). You will want your switches to be NO, so ignore the NC prongs, they will all be labeled. The Cthulhu board will come with screw connectors which will eliminate the need for soldering, and the pins will be documented in a seperate sheet of paper that comes with the unit (you can buy it from LizardLick.com).
Buy some femal quick connectors that will fit the size of the miscroswitch prongs, use these to connect all your wire to the microswithces. Connect all of the GND prongs on all the switches to EACHOTHER, then run one wire from any of the GND prongs to the gnd pin on the Cthulhu (or if you're doing a pad hack opend the plastic case and expose just the printed circuit board (PCB). you can see all the leads that make the buttons work. for each button there are two exposed metal leads that are seperated. when you press a button it connects the two leads and sends a signal to the game. For each button, one side is GND and one is the signal lead. you can tell which is GND becase it will be connected to all the other GNDS of the other buttons. just try to follow the leads... solder the GND wire to any GND on the pad, assuming you have a common GND pad. If you solder USE FLUX, or you will not get the wire to make a good connection to the pad. I know from experience.). Now run one wire from each other switche's NO prong to the appropriate pin on the Cthulhu (or pad). Remember that on a stick when you move it in the up direction you are actually pressing the down microswitch, and when you move left you are pressing the right microswitch etc... So reverse up/down and left/right.
If this doesn't make sense there are plenty of tutorials online with pics and stuff. But if you can understand this you should be able to get it done.